The problem I see with digiscope photography is that while spotting scopes are excellent for their primary function, they are too slow for wildlife photography. If it were me and I was really intent on making it work, I'd use a remote trigger, a Wimberly type head, and the highest ISO I thought I could reasonably get away with. Birds in flight are a complicated subspecialty of wildlife photography and are one of the reasons for the existence of fast, long lenses that cost many thousands. If you were shooting stationary wildlife, you could go the other way and set the exposure to be long enough that the failings of the slow scope didn't affect the final photo as much. Some animals will stay completely motionless for seconds at a time making this possible. Birds in flight not so much.
